The present invention relates to a crash box for placement between a bumper beam and a side rail of a motor vehicle, and to a bumper provided with such a crash box.
Nothing in the following discussion of the state of the art is to be construed as an admission of prior art.
A standard bumper is typically mounted on the front or rear of a motor vehicle to absorb impact energy and thereby prevent damage to the vehicle structure in the event of a frontal or rear impact. The bumper typically includes a bumper beam which is mounted to the side rails of the vehicle frame through intervention of crash boxes. The bumper beam is provided to introduce energy, generated in the event of a collision, into the crash boxes which convert the impact energy into deformation work. The bumper structure is typically constructed in such a manner that the crash boxes are typically situated in midsection on the side rails and the impact energy is transferred via the bumper beam with smallest possible flexing into the crash boxes and ultimately into the side rails.
German Offenlegungsschrift DE 43 16 164 A1 describes a bumper which includes a slide-in tube made of two longitudinal sections of different cross sections. The longitudinal section with the smaller cross-section is fixedly connected to the bumper beam, whereas the longitudinal section with the greater cross section is mounted on the chassis of the motor vehicle. In the event of an impact, the smaller longitudinal section deforms into the greater longitudinal section, causing the wall of the longer section to fold back and to roll off the greater longitudinal section. Slide-in tubes of this type afford only little lateral stiffness.
A problem common to conventional bumpers is the fact that the available space for energy absorption is not utilized effectively in the event of an impact because the crash boxes form a block when deformed, thereby reducing the deformation path.
It would therefore be desirable and advantageous to address this problem and to obviate other prior art shortcomings.